Better yet, what should I do to assess the existing wiring in my home? As I redo the kitchen and bath I'll be putting in a subpanel with many new circuits, but what about the old ones that will remain for elsewhere in the house? What kind of tests can be done, what should be looked at?

The house was built in the early 20s, and in the early 70s went to breakers and several circuits were added by running conduit around the exterior to distribute the power to receptacles. I'm not too worried about the 70s stuff, but the 20s stuff that remains scares me. Especially with what i found stuffed into a couple boxes that I removed already.

A quick way to apply a 12.5 amp load is to get a small portable room heater rated at 1500 watts. This would give you some idea.

We live in a small condo, and rather than run the gas forced air unit, are content to heat our place with 1 or 2 portable oil filled radiators. Usually it is one, but on a really fierce San Diego winter night ( temp down to 35ÂºF) we might have 2. Last year, I noted the the plugs were warm when running. I cut off the factory plug and installed a heavy duty replacement, and also replaced the builder-grade receptacle with a commercial grade. Now, the cord, the plug, and the receptacle box, stay cool as a cucumber.

Naturally, we have to be selective where to plug these in. I first found that a convenient receptacle in the living room was also tied to the kitchen cofee pot! That doen't work. There is a dedicated wall A/C outlet, so I use that one. In the bed/bath area, just can't use the hair dryer at the same time!

Existing wiring is tested with a High potential tester refered to as a megger (megger is actually a brand name). Ths instrument utilizes a 1000 Volts DC and gives a reading in megohms (one megohm = 1,000,000 ohns).